1. Field of the Invention
The present invention relates to a movable part locking jig and a portable image forming apparatus incorporating such a movable part locking jig therein.
2. Description of the Related Art
There has been known in the art an X-ray photographic film for use as an image recording medium for recording radiation image information of a subject such as a human being. There has also been widely used a stimulable phosphor panel instead of the X-ray photographic film. The stimulable phosphor panel has a stimulable phosphor layer which, when exposed to an applied radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet radiation, or the like), stores part of the energy of the radiation, and, when subsequently exposed to stimulating rays such as laser beam or visible light, emits stimulated light in proportion to the stored energy of the radiation.
These image recording mediums are usually handled while being housed in a light-shielded cassette or magazine. The cassette is structured to house a single image recording medium in the form of a sheet therein. The cassette is employed by a system having a cassette-compatible image information reading apparatus (image forming apparatus) comprising a cassette loader for loading a cassette which houses therein an image recording medium with radiation image information recorded therein, a reading unit for reading the radiation image information recorded in the image recording medium removed from the cassette, and an erasing unit for erasing remaining radiation image information from the image recording medium.
If the above image information reading apparatus is small and portable (hereinafter referred to as “mobile image information reading apparatus”), then it may be moved to an image recording site where a subject may be imaged and recorded radiation image information may be read. For example, after a subject is imaged and radiation image information of the subject is recorded in a stimulable phosphor panel, the recorded radiation image information is immediately read and displayed on a display unit for observation in an operation room or the like. Even if a patient has a body region or an afflicted region which is difficult to image properly, the mobile image information reading apparatus may be moved to the patient to capture radiation image information of the patient. After the radiation image information is captured, it may immediately be read for confirming or adjusting image capturing conditions. As a result, the patient can quickly and accurately be diagnosed.
Since the mobile image information reading apparatus is free of installation site limitations, the same image recording and reading operation as the conventional fixed image information reading apparatus can be performed by fewer mobile image information reading apparatus than the conventional fixed image information reading apparatus. Therefore, there are demands for highly efficient mobile image information reading apparatus in hospitals.
When a mobile image information reading apparatus is moved around in a hospital, some vibrations are inevitably applied to the mobile image information reading apparatus. Since the mobile image information reading apparatus is handled in different places, it may be subject to unexpected shocks in certain locations.
If the mobile image information reading apparatus, which is a precision apparatus, undergoes vibrations or shocks, it tends to have mechanical trouble such as loose screws or the like, which may lead to erroneous reading of recorded radiation image information. Such a reading error greatly affects the image quality of the radiation image information. If the applied vibrations or shocks are extremely intensive, then the mobile image information reading apparatus itself fails to operate. As a result, the availability factor of the mobile image information reading apparatus is lowered to the extent that the convenience of the mobile image information reading apparatus is lost, losing its convenience.
For moving the mobile image information reading apparatus, therefore, it is important to take measures to make movable units that require high accuracy resistant to vibrations and shocks, such as a reading unit for scanning and reading an image recording medium and a supply unit having suction cups for attracting and removing an image recording medium from a cassette and supplying the removed image recording medium to the reading unit.
For example, Japanese Laid-Open Patent Publication No. 2004-184905 discloses an image information reading apparatus wherein a clutch brake is coupled to a drive source for moving a reading head as a movable unit. When a main power supply of the image information reading apparatus is turned off, the supply of electric power to the clutch brake is cut off to lock the drive source for thereby preventing the reading head from moving.
However, since the clutch brake is disposed in the image information reading apparatus, the image information reading apparatus is heavy in weight and large in size. Therefore, it is difficult for the disclosed image information reading apparatus to satisfy requirements for small, lightweight mobile image information reading apparatus. In addition, as the reading head is not locked itself, it is not completely free of vibrations and shocks.
The same problems also arise in image information recording apparatus (image forming apparatus) in which an image recording medium such as an X-ray photographic film is supplied to a recording unit and radiation image information is recorded in the image recording medium by the recording unit.